// SPDX-License-Identifier: GPL-2.0
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <media/v4l2-subdev.h>
#include <linux/mfd/intel_soc_pmic.h>
#include <linux/regulator/consumer.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>
#include "../../include/linux/atomisp_platform.h"
#include "../../include/linux/atomisp_gmin_platform.h"

#define MAX_SUBDEVS 8

enum clock_rate {
        VLV2_CLK_XTAL_25_0MHz = 0,
        VLV2_CLK_PLL_19P2MHZ = 1
};

#define CLK_RATE_19_2MHZ        19200000
#define CLK_RATE_25_0MHZ        25000000

/* Valid clock number range from 0 to 5 */
#define MAX_CLK_COUNT                   5

/* X-Powers AXP288 register set */
#define ALDO1_SEL_REG   0x28
#define ALDO1_CTRL3_REG 0x13
#define ALDO1_2P8V      0x16
#define ALDO1_CTRL3_SHIFT 0x05

#define ELDO_CTRL_REG   0x12

#define ELDO1_SEL_REG   0x19
#define ELDO1_1P6V      0x12
#define ELDO1_CTRL_SHIFT 0x00

#define ELDO2_SEL_REG   0x1a
#define ELDO2_1P8V      0x16
#define ELDO2_CTRL_SHIFT 0x01

/* TI SND9039 PMIC register set */
#define LDO9_REG        0x49
#define LDO10_REG       0x4a
#define LDO11_REG       0x4b

#define LDO_2P8V_ON     0x2f /* 0x2e selects 2.85V ...      */
#define LDO_2P8V_OFF    0x2e /* ... bottom bit is "enabled" */

#define LDO_1P8V_ON     0x59 /* 0x58 selects 1.80V ...      */
#define LDO_1P8V_OFF    0x58 /* ... bottom bit is "enabled" */

/* CRYSTAL COVE PMIC register set */
#define CRYSTAL_1P8V_REG        0x57
#define CRYSTAL_2P8V_REG        0x5d
#define CRYSTAL_ON              0x63
#define CRYSTAL_OFF             0x62

struct gmin_subdev {
        struct v4l2_subdev *subdev;
        enum clock_rate clock_src;
        struct clk *pmc_clk;
        struct gpio_desc *gpio0;
        struct gpio_desc *gpio1;
        struct regulator *v1p8_reg;
        struct regulator *v2p8_reg;
        struct regulator *v1p2_reg;
        struct regulator *v2p8_vcm_reg;
        enum atomisp_camera_port csi_port;
        unsigned int csi_lanes;
        enum atomisp_input_format csi_fmt;
        enum atomisp_bayer_order csi_bayer;

        bool clock_on;
        bool v1p8_on;
        bool v2p8_on;
        bool v1p2_on;
        bool v2p8_vcm_on;

        int v1p8_gpio;
        int v2p8_gpio;

        u8 pwm_i2c_addr;

        /* For PMIC AXP */
        int eldo1_sel_reg, eldo1_1p6v, eldo1_ctrl_shift;
        int eldo2_sel_reg, eldo2_1p8v, eldo2_ctrl_shift;
};

static struct gmin_subdev gmin_subdevs[MAX_SUBDEVS];

/* ACPI HIDs for the PMICs that could be used by this driver */
#define PMIC_ACPI_AXP           "INT33F4"       /* XPower AXP288 PMIC */
#define PMIC_ACPI_TI            "INT33F5"       /* Dollar Cove TI PMIC */
#define PMIC_ACPI_CRYSTALCOVE   "INT33FD"       /* Crystal Cove PMIC */

#define PMIC_PLATFORM_TI        "intel_soc_pmic_chtdc_ti"

static enum {
        PMIC_UNSET = 0,
        PMIC_REGULATOR,
        PMIC_AXP,
        PMIC_TI,
        PMIC_CRYSTALCOVE
} pmic_id;

static const char *pmic_name[] = {
        [PMIC_UNSET]            = "ACPI device PM",
        [PMIC_REGULATOR]        = "regulator driver",
        [PMIC_AXP]              = "XPower AXP288 PMIC",
        [PMIC_TI]               = "Dollar Cove TI PMIC",
        [PMIC_CRYSTALCOVE]      = "Crystal Cove PMIC",
};

static DEFINE_MUTEX(gmin_regulator_mutex);
static int gmin_v1p8_enable_count;
static int gmin_v2p8_enable_count;

/* The atomisp uses type==0 for the end-of-list marker, so leave space. */
static struct intel_v4l2_subdev_table pdata_subdevs[MAX_SUBDEVS + 1];

static const struct atomisp_platform_data pdata = {
        .subdevs = pdata_subdevs,
};

static LIST_HEAD(vcm_devices);
static DEFINE_MUTEX(vcm_lock);

static struct gmin_subdev *find_gmin_subdev(struct v4l2_subdev *subdev);

/*
 * Legacy/stub behavior copied from upstream platform_camera.c.  The
 * atomisp driver relies on these values being non-NULL in a few
 * places, even though they are hard-coded in all current
 * implementations.
 */
const struct atomisp_camera_caps *atomisp_get_default_camera_caps(void)
{
        static const struct atomisp_camera_caps caps = {
                .sensor_num = 1,
                .sensor = {
                        { .stream_num = 1, },
                },
        };
        return &caps;
}
EXPORT_SYMBOL_GPL(atomisp_get_default_camera_caps);

const struct atomisp_platform_data *atomisp_get_platform_data(void)
{
        return &pdata;
}
EXPORT_SYMBOL_GPL(atomisp_get_platform_data);

int atomisp_register_i2c_module(struct v4l2_subdev *subdev,
                                struct camera_sensor_platform_data *plat_data,
                                enum intel_v4l2_subdev_type type)
{
        int i;
        struct i2c_board_info *bi;
        struct gmin_subdev *gs;
        struct i2c_client *client = v4l2_get_subdevdata(subdev);
        struct acpi_device *adev = ACPI_COMPANION(&client->dev);

        dev_info(&client->dev, "register atomisp i2c module type %d\n", type);

        /* The windows driver model (and thus most BIOSes by default)
         * uses ACPI runtime power management for camera devices, but
         * we don't.  Disable it, or else the rails will be needlessly
         * tickled during suspend/resume.  This has caused power and
         * performance issues on multiple devices.
         */
        adev->power.flags.power_resources = 0;

        for (i = 0; i < MAX_SUBDEVS; i++)
                if (!pdata.subdevs[i].type)
                        break;

        if (pdata.subdevs[i].type)
                return -ENOMEM;

        /* Note subtlety of initialization order: at the point where
         * this registration API gets called, the platform data
         * callbacks have probably already been invoked, so the
         * gmin_subdev struct is already initialized for us.
         */
        gs = find_gmin_subdev(subdev);
        if (!gs)
                return -ENODEV;

        pdata.subdevs[i].type = type;
        pdata.subdevs[i].port = gs->csi_port;
        pdata.subdevs[i].subdev = subdev;
        pdata.subdevs[i].v4l2_subdev.i2c_adapter_id = client->adapter->nr;

        /* Convert i2c_client to i2c_board_info */
        bi = &pdata.subdevs[i].v4l2_subdev.board_info;
        memcpy(bi->type, client->name, I2C_NAME_SIZE);
        bi->flags = client->flags;
        bi->addr = client->addr;
        bi->irq = client->irq;
        bi->platform_data = plat_data;

        return 0;
}
EXPORT_SYMBOL_GPL(atomisp_register_i2c_module);

struct v4l2_subdev *atomisp_gmin_find_subdev(struct i2c_adapter *adapter,
        struct i2c_board_info *board_info)
{
        int i;

        for (i = 0; i < MAX_SUBDEVS && pdata.subdevs[i].type; i++) {
                struct intel_v4l2_subdev_table *sd = &pdata.subdevs[i];

                if (sd->v4l2_subdev.i2c_adapter_id == adapter->nr &&
                    sd->v4l2_subdev.board_info.addr == board_info->addr)
                        return sd->subdev;
        }
        return NULL;
}
EXPORT_SYMBOL_GPL(atomisp_gmin_find_subdev);

int atomisp_gmin_remove_subdev(struct v4l2_subdev *sd)
{
        int i, j;

        if (!sd)
                return 0;

        for (i = 0; i < MAX_SUBDEVS; i++) {
                if (pdata.subdevs[i].subdev == sd) {
                        for (j = i + 1; j <= MAX_SUBDEVS; j++)
                                pdata.subdevs[j - 1] = pdata.subdevs[j];
                }
                if (gmin_subdevs[i].subdev == sd) {
                        if (gmin_subdevs[i].gpio0)
                                gpiod_put(gmin_subdevs[i].gpio0);
                        gmin_subdevs[i].gpio0 = NULL;
                        if (gmin_subdevs[i].gpio1)
                                gpiod_put(gmin_subdevs[i].gpio1);
                        gmin_subdevs[i].gpio1 = NULL;
                        if (pmic_id == PMIC_REGULATOR) {
                                regulator_put(gmin_subdevs[i].v1p8_reg);
                                regulator_put(gmin_subdevs[i].v2p8_reg);
                                regulator_put(gmin_subdevs[i].v1p2_reg);
                                regulator_put(gmin_subdevs[i].v2p8_vcm_reg);
                        }
                        gmin_subdevs[i].subdev = NULL;
                }
        }
        return 0;
}
EXPORT_SYMBOL_GPL(atomisp_gmin_remove_subdev);

struct gmin_cfg_var {
        const char *name, *val;
};

static struct gmin_cfg_var ffrd8_vars[] = {
        { "INTCF1B:00_ImxId",    "0x134" },
        { "INTCF1B:00_CsiPort",  "1" },
        { "INTCF1B:00_CsiLanes", "4" },
        { "INTCF1B:00_CamClk", "0" },
        {},
};

/* Cribbed from MCG defaults in the mt9m114 driver, not actually verified
 * vs. T100 hardware
 */
static struct gmin_cfg_var t100_vars[] = {
        { "INT33F0:00_CsiPort",  "0" },
        { "INT33F0:00_CsiLanes", "1" },
        { "INT33F0:00_CamClk",   "1" },
        {},
};

static struct gmin_cfg_var mrd7_vars[] = {
        {"INT33F8:00_CamType", "1"},
        {"INT33F8:00_CsiPort", "1"},
        {"INT33F8:00_CsiLanes", "2"},
        {"INT33F8:00_CsiFmt", "13"},
        {"INT33F8:00_CsiBayer", "0"},
        {"INT33F8:00_CamClk", "0"},

        {"INT33F9:00_CamType", "1"},
        {"INT33F9:00_CsiPort", "0"},
        {"INT33F9:00_CsiLanes", "1"},
        {"INT33F9:00_CsiFmt", "13"},
        {"INT33F9:00_CsiBayer", "0"},
        {"INT33F9:00_CamClk", "1"},
        {},
};

static struct gmin_cfg_var ecs7_vars[] = {
        {"INT33BE:00_CsiPort", "1"},
        {"INT33BE:00_CsiLanes", "2"},
        {"INT33BE:00_CsiFmt", "13"},
        {"INT33BE:00_CsiBayer", "2"},
        {"INT33BE:00_CamClk", "0"},

        {"INT33F0:00_CsiPort", "0"},
        {"INT33F0:00_CsiLanes", "1"},
        {"INT33F0:00_CsiFmt", "13"},
        {"INT33F0:00_CsiBayer", "0"},
        {"INT33F0:00_CamClk", "1"},
        {"gmin_V2P8GPIO", "402"},
        {},
};

static struct gmin_cfg_var i8880_vars[] = {
        {"XXOV2680:00_CsiPort", "1"},
        {"XXOV2680:00_CsiLanes", "1"},
        {"XXOV2680:00_CamClk", "0"},

        {"XXGC0310:00_CsiPort", "0"},
        {"XXGC0310:00_CsiLanes", "1"},
        {"XXGC0310:00_CamClk", "1"},
        {},
};

/*
 * Surface 3 does not describe CsiPort/CsiLanes in both DSDT and EFI.
 */
static struct gmin_cfg_var surface3_vars[] = {
        {"APTA0330:00_CsiPort", "0"},
        {"APTA0330:00_CsiLanes", "2"},

        {"OVTI8835:00_CsiPort", "1"},
        {"OVTI8835:00_CsiLanes", "4"},
        {},
};

static const struct dmi_system_id gmin_vars[] = {
        {
                .ident = "BYT-T FFD8",
                .matches = {
                        DMI_MATCH(DMI_BOARD_NAME, "BYT-T FFD8"),
                },
                .driver_data = ffrd8_vars,
        },
        {
                .ident = "T100TA",
                .matches = {
                        DMI_MATCH(DMI_BOARD_NAME, "T100TA"),
                },
                .driver_data = t100_vars,
        },
        {
                .ident = "MRD7",
                .matches = {
                        DMI_MATCH(DMI_BOARD_NAME, "TABLET"),
                        DMI_MATCH(DMI_BOARD_VERSION, "MRD 7"),
                },
                .driver_data = mrd7_vars,
        },
        {
                .ident = "ST70408",
                .matches = {
                        DMI_MATCH(DMI_BOARD_NAME, "ST70408"),
                },
                .driver_data = ecs7_vars,
        },
        {
                .ident = "VTA0803",
                .matches = {
                        DMI_MATCH(DMI_BOARD_NAME, "VTA0803"),
                },
                .driver_data = i8880_vars,
        },
        {
                .ident = "Surface 3",
                .matches = {
                        DMI_MATCH(DMI_BOARD_NAME, "Surface 3"),
                },
                .driver_data = surface3_vars,
        },
        {}
};

#define GMIN_CFG_VAR_EFI_GUID EFI_GUID(0xecb54cd9, 0xe5ae, 0x4fdc, \
                                       0xa9, 0x71, 0xe8, 0x77,     \
                                       0x75, 0x60, 0x68, 0xf7)

static const guid_t atomisp_dsm_guid = GUID_INIT(0xdc2f6c4f, 0x045b, 0x4f1d,
                                                 0x97, 0xb9, 0x88, 0x2a,
                                                 0x68, 0x60, 0xa4, 0xbe);

#define CFG_VAR_NAME_MAX 64

#define GMIN_PMC_CLK_NAME 14 /* "pmc_plt_clk_[0..5]" */
static char gmin_pmc_clk_name[GMIN_PMC_CLK_NAME];

static struct i2c_client *gmin_i2c_dev_exists(struct device *dev, char *name,
                                              struct i2c_client **client)
{
        struct acpi_device *adev;
        struct device *d;

        adev = acpi_dev_get_first_match_dev(name, NULL, -1);
        if (!adev)
                return NULL;

        d = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
        acpi_dev_put(adev);
        if (!d)
                return NULL;

        *client = i2c_verify_client(d);
        put_device(d);

        dev_dbg(dev, "found '%s' at address 0x%02x, adapter %d\n",
                (*client)->name, (*client)->addr, (*client)->adapter->nr);
        return *client;
}

static int gmin_i2c_write(struct device *dev, u16 i2c_addr, u8 reg,
                          u32 value, u32 mask)
{
        int ret;

        /*
         * FIXME: Right now, the intel_pmic driver just write values
         * directly at the regmap, instead of properly implementing
         * i2c_transfer() mechanism. Let's use the same interface here,
         * as otherwise we may face issues.
         */

        dev_dbg(dev,
                "I2C write, addr: 0x%02x, reg: 0x%02x, value: 0x%02x, mask: 0x%02x\n",
                i2c_addr, reg, value, mask);

        ret = intel_soc_pmic_exec_mipi_pmic_seq_element(i2c_addr, reg, value, mask);
        if (ret == -EOPNOTSUPP)
                dev_err(dev,
                        "ACPI didn't mapped the OpRegion needed to access I2C address 0x%02x.\n"
                        "Need to compile the kernel using CONFIG_*_PMIC_OPREGION settings\n",
                        i2c_addr);

        return ret;
}

static int atomisp_get_acpi_power(struct device *dev)
{
        char name[5];
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        struct acpi_buffer b_name = { sizeof(name), name };
        union acpi_object *package, *element;
        acpi_handle handle = ACPI_HANDLE(dev);
        acpi_handle rhandle;
        acpi_status status;
        int clock_num = -1;
        int i;

        status = acpi_evaluate_object(handle, "_PR0", NULL, &buffer);
        if (!ACPI_SUCCESS(status))
                return -1;

        package = buffer.pointer;

        if (!buffer.length || !package
            || package->type != ACPI_TYPE_PACKAGE
            || !package->package.count)
                goto fail;

        for (i = 0; i < package->package.count; i++) {
                element = &package->package.elements[i];

                if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
                        continue;

                rhandle = element->reference.handle;
                if (!rhandle)
                        goto fail;

                acpi_get_name(rhandle, ACPI_SINGLE_NAME, &b_name);

                dev_dbg(dev, "Found PM resource '%s'\n", name);
                if (strlen(name) == 4 && !strncmp(name, "CLK", 3)) {
                        if (name[3] >= '0' && name[3] <= '4')
                                clock_num = name[3] - '0';
#if 0
                        /*
                         * We could abort here, but let's parse all resources,
                         * as this is helpful for debugging purposes
                         */
                        if (clock_num >= 0)
                                break;
#endif
                }
        }

fail:
        ACPI_FREE(buffer.pointer);

        return clock_num;
}

static u8 gmin_get_pmic_id_and_addr(struct device *dev)
{
        struct i2c_client *power = NULL;
        static u8 pmic_i2c_addr;

        if (pmic_id)
                return pmic_i2c_addr;

        if (gmin_i2c_dev_exists(dev, PMIC_ACPI_TI, &power))
                pmic_id = PMIC_TI;
        else if (gmin_i2c_dev_exists(dev, PMIC_ACPI_AXP, &power))
                pmic_id = PMIC_AXP;
        else if (gmin_i2c_dev_exists(dev, PMIC_ACPI_CRYSTALCOVE, &power))
                pmic_id = PMIC_CRYSTALCOVE;
        else
                pmic_id = PMIC_REGULATOR;

        pmic_i2c_addr = power ? power->addr : 0;
        return pmic_i2c_addr;
}

static int gmin_detect_pmic(struct v4l2_subdev *subdev)
{
        struct i2c_client *client = v4l2_get_subdevdata(subdev);
        struct device *dev = &client->dev;
        u8 pmic_i2c_addr;

        pmic_i2c_addr = gmin_get_pmic_id_and_addr(dev);
        dev_info(dev, "gmin: power management provided via %s (i2c addr 0x%02x)\n",
                 pmic_name[pmic_id], pmic_i2c_addr);
        return pmic_i2c_addr;
}

static int gmin_subdev_add(struct gmin_subdev *gs)
{
        struct i2c_client *client = v4l2_get_subdevdata(gs->subdev);
        struct device *dev = &client->dev;
        struct acpi_device *adev = ACPI_COMPANION(dev);
        int ret, default_val, clock_num = -1;

        dev_info(dev, "%s: ACPI path is %pfw\n", __func__, dev_fwnode(dev));

        /*WA:CHT requires XTAL clock as PLL is not stable.*/
        gs->clock_src = gmin_get_var_int(dev, false, "ClkSrc",
                                         VLV2_CLK_PLL_19P2MHZ);

        /*
         * Get ACPI _PR0 derived clock here already because it is used
         * to determine the csi_port default.
         */
        if (acpi_device_power_manageable(adev))
                clock_num = atomisp_get_acpi_power(dev);

        /* Compare clock to CsiPort 1 pmc-clock used in the CHT/BYT reference designs */
        if (IS_ISP2401)
                default_val = clock_num == 4 ? 1 : 0;
        else
                default_val = clock_num == 0 ? 1 : 0;

        gs->csi_port = gmin_get_var_int(dev, false, "CsiPort", default_val);
        gs->csi_lanes = gmin_get_var_int(dev, false, "CsiLanes", 1);

        gs->gpio0 = gpiod_get_index(dev, NULL, 0, GPIOD_OUT_LOW);
        if (IS_ERR(gs->gpio0))
                gs->gpio0 = NULL;
        else
                dev_info(dev, "will handle gpio0 via ACPI\n");

        gs->gpio1 = gpiod_get_index(dev, NULL, 1, GPIOD_OUT_LOW);
        if (IS_ERR(gs->gpio1))
                gs->gpio1 = NULL;
        else
                dev_info(dev, "will handle gpio1 via ACPI\n");

        /*
         * Those are used only when there is an external regulator apart
         * from the PMIC that would be providing power supply, like on the
         * two cases below:
         *
         * The ECS E7 board drives camera 2.8v from an external regulator
         * instead of the PMIC.  There's a gmin_CamV2P8 config variable
         * that specifies the GPIO to handle this particular case,
         * but this needs a broader architecture for handling camera power.
         *
         * The CHT RVP board drives camera 1.8v from an* external regulator
         * instead of the PMIC just like ECS E7 board.
         */

        gs->v1p8_gpio = gmin_get_var_int(dev, true, "V1P8GPIO", -1);
        gs->v2p8_gpio = gmin_get_var_int(dev, true, "V2P8GPIO", -1);

        /*
         * FIXME:
         *
         * The ACPI handling code checks for the _PR? tables in order to
         * know what is required to switch the device from power state
         * D0 (_PR0) up to D3COLD (_PR3).
         *
         * The adev->flags.power_manageable is set to true if the device
         * has a _PR0 table, which can be checked by calling
         * acpi_device_power_manageable(adev).
         *
         * However, this only says that the device can be set to power off
         * mode.
         *
         * At least on the DSDT tables we've seen so far, there's no _PR3,
         * nor _PS3 (which would have a somewhat similar effect).
         * So, using ACPI for power management won't work, except if adding
         * an ACPI override logic somewhere.
         *
         * So, at least for the existing devices we know, the check below
         * will always be false.
         */
        if (acpi_device_can_wakeup(adev) &&
            acpi_device_can_poweroff(adev)) {
                dev_info(dev,
                         "gmin: power management provided via device PM\n");
                return 0;
        }

        /*
         * The code below is here due to backward compatibility with devices
         * whose ACPI BIOS may not contain everything that would be needed
         * in order to set clocks and do power management.
         */

        /*
         * According with :
         *   https://github.com/projectceladon/hardware-intel-kernelflinger/blob/master/doc/fastboot.md
         *
         * The "CamClk" EFI var is set via fastboot on some Android devices,
         * and seems to contain the number of the clock used to feed the
         * sensor.
         *
         * On systems with a proper ACPI table, this is given via the _PR0
         * power resource table. The logic below should first check if there
         * is a power resource already, falling back to the EFI vars detection
         * otherwise.
         */

        /* If getting the clock from _PR0 above failed, fall-back to EFI and/or DMI match */
        if (clock_num < 0)
                clock_num = gmin_get_var_int(dev, false, "CamClk", 0);

        if (clock_num < 0 || clock_num > MAX_CLK_COUNT) {
                dev_err(dev, "Invalid clock number\n");
                return -EINVAL;
        }

        snprintf(gmin_pmc_clk_name, sizeof(gmin_pmc_clk_name),
                 "%s_%d", "pmc_plt_clk", clock_num);

        gs->pmc_clk = devm_clk_get(dev, gmin_pmc_clk_name);
        if (IS_ERR(gs->pmc_clk)) {
                ret = PTR_ERR(gs->pmc_clk);
                dev_err(dev, "Failed to get clk from %s: %d\n", gmin_pmc_clk_name, ret);
                return ret;
        }
        dev_info(dev, "Will use CLK%d (%s)\n", clock_num, gmin_pmc_clk_name);

        /*
         * The firmware might enable the clock at
         * boot (this information may or may not
         * be reflected in the enable clock register).
         * To change the rate we must disable the clock
         * first to cover these cases. Due to common
         * clock framework restrictions that do not allow
         * to disable a clock that has not been enabled,
         * we need to enable the clock first.
         */
        ret = clk_prepare_enable(gs->pmc_clk);
        if (!ret)
                clk_disable_unprepare(gs->pmc_clk);

        switch (pmic_id) {
        case PMIC_REGULATOR:
                gs->v1p8_reg = regulator_get(dev, "V1P8SX");
                gs->v2p8_reg = regulator_get(dev, "V2P8SX");

                gs->v1p2_reg = regulator_get(dev, "V1P2A");
                gs->v2p8_vcm_reg = regulator_get(dev, "VPROG4B");

                /* Note: ideally we would initialize v[12]p8_on to the
                 * output of regulator_is_enabled(), but sadly that
                 * API is broken with the current drivers, returning
                 * "1" for a regulator that will then emit a
                 * "unbalanced disable" WARNing if we try to disable
                 * it.
                 */
                break;

        case PMIC_AXP:
                gs->eldo1_1p6v = gmin_get_var_int(dev, false,
                                                  "eldo1_1p8v",
                                                  ELDO1_1P6V);
                gs->eldo1_sel_reg = gmin_get_var_int(dev, false,
                                                     "eldo1_sel_reg",
                                                     ELDO1_SEL_REG);
                gs->eldo1_ctrl_shift = gmin_get_var_int(dev, false,
                                                        "eldo1_ctrl_shift",
                                                        ELDO1_CTRL_SHIFT);
                gs->eldo2_1p8v = gmin_get_var_int(dev, false,
                                                  "eldo2_1p8v",
                                                  ELDO2_1P8V);
                gs->eldo2_sel_reg = gmin_get_var_int(dev, false,
                                                     "eldo2_sel_reg",
                                                     ELDO2_SEL_REG);
                gs->eldo2_ctrl_shift = gmin_get_var_int(dev, false,
                                                        "eldo2_ctrl_shift",
                                                        ELDO2_CTRL_SHIFT);
                break;

        default:
                break;
        }

        return 0;
}

static struct gmin_subdev *find_gmin_subdev(struct v4l2_subdev *subdev)
{
        int i;

        for (i = 0; i < MAX_SUBDEVS; i++)
                if (gmin_subdevs[i].subdev == subdev)
                        return &gmin_subdevs[i];
        return NULL;
}

static struct gmin_subdev *find_free_gmin_subdev_slot(void)
{
        unsigned int i;

        for (i = 0; i < MAX_SUBDEVS; i++)
                if (gmin_subdevs[i].subdev == NULL)
                        return &gmin_subdevs[i];
        return NULL;
}

static int axp_regulator_set(struct device *dev, struct gmin_subdev *gs,
                             int sel_reg, u8 setting,
                             int ctrl_reg, int shift, bool on)
{
        int ret;
        int val;

        ret = gmin_i2c_write(dev, gs->pwm_i2c_addr, sel_reg, setting, 0xff);
        if (ret)
                return ret;

        val = on ? 1 << shift : 0;

        ret = gmin_i2c_write(dev, gs->pwm_i2c_addr, ctrl_reg, val, 1 << shift);
        if (ret)
                return ret;

        return 0;
}

/*
 * Some boards contain a hw-bug where turning eldo2 back on after having turned
 * it off causes the CPLM3218 ambient-light-sensor on the image-sensor's I2C bus
 * to crash, hanging the bus. Do not turn eldo2 off on these systems.
 */
static const struct dmi_system_id axp_leave_eldo2_on_ids[] = {
        {
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "TrekStor"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "SurfTab duo W1 10.1 (VT4)"),
                },
        },
        { }
};

static int axp_v1p8_on(struct device *dev, struct gmin_subdev *gs)
{
        int ret;

        ret = axp_regulator_set(dev, gs, gs->eldo2_sel_reg, gs->eldo2_1p8v,
                                ELDO_CTRL_REG, gs->eldo2_ctrl_shift, true);
        if (ret)
                return ret;

        /*
         * This sleep comes out of the gc2235 driver, which is the
         * only one I currently see that wants to set both 1.8v rails.
         */
        usleep_range(110, 150);

        ret = axp_regulator_set(dev, gs, gs->eldo1_sel_reg, gs->eldo1_1p6v,
                                ELDO_CTRL_REG, gs->eldo1_ctrl_shift, true);
        return ret;
}

static int axp_v1p8_off(struct device *dev, struct gmin_subdev *gs)
{
        int ret;

        ret = axp_regulator_set(dev, gs, gs->eldo1_sel_reg, gs->eldo1_1p6v,
                                ELDO_CTRL_REG, gs->eldo1_ctrl_shift, false);
        if (ret)
                return ret;

        if (dmi_check_system(axp_leave_eldo2_on_ids))
                return 0;

        ret = axp_regulator_set(dev, gs, gs->eldo2_sel_reg, gs->eldo2_1p8v,
                                ELDO_CTRL_REG, gs->eldo2_ctrl_shift, false);
        return ret;
}

static int gmin_gpio0_ctrl(struct v4l2_subdev *subdev, int on)
{
        struct gmin_subdev *gs = find_gmin_subdev(subdev);

        if (gs) {
                gpiod_set_value(gs->gpio0, on);
                return 0;
        }
        return -EINVAL;
}

static int gmin_gpio1_ctrl(struct v4l2_subdev *subdev, int on)
{
        struct gmin_subdev *gs = find_gmin_subdev(subdev);

        if (gs) {
                gpiod_set_value(gs->gpio1, on);
                return 0;
        }
        return -EINVAL;
}

static int gmin_v1p2_ctrl(struct v4l2_subdev *subdev, int on)
{
        struct gmin_subdev *gs = find_gmin_subdev(subdev);

        if (!gs || gs->v1p2_on == on)
                return 0;
        gs->v1p2_on = on;

        /* use regulator for PMIC */
        if (gs->v1p2_reg) {
                if (on)
                        return regulator_enable(gs->v1p2_reg);
                else
                        return regulator_disable(gs->v1p2_reg);
        }

        /* TODO:v1p2 may need to extend to other PMICs */

        return -EINVAL;
}

static int gmin_v1p8_ctrl(struct v4l2_subdev *subdev, int on)
{
        struct gmin_subdev *gs = find_gmin_subdev(subdev);
        int ret;
        int value;

        if (!gs || gs->v1p8_on == on)
                return 0;

        if (gs->v1p8_gpio >= 0) {
                pr_info("atomisp_gmin_platform: 1.8v power on GPIO %d\n",
                        gs->v1p8_gpio);
                ret = gpio_request(gs->v1p8_gpio, "camera_v1p8_en");
                if (!ret)
                        ret = gpio_direction_output(gs->v1p8_gpio, 0);
                if (ret)
                        pr_err("V1P8 GPIO initialization failed\n");
        }

        gs->v1p8_on = on;

        ret = 0;
        mutex_lock(&gmin_regulator_mutex);
        if (on) {
                gmin_v1p8_enable_count++;
                if (gmin_v1p8_enable_count > 1)
                        goto out; /* Already on */
        } else {
                gmin_v1p8_enable_count--;
                if (gmin_v1p8_enable_count > 0)
                        goto out; /* Still needed */
        }

        if (gs->v1p8_gpio >= 0)
                gpio_set_value(gs->v1p8_gpio, on);

        if (gs->v1p8_reg) {
                regulator_set_voltage(gs->v1p8_reg, 1800000, 1800000);
                if (on)
                        ret = regulator_enable(gs->v1p8_reg);
                else
                        ret = regulator_disable(gs->v1p8_reg);

                goto out;
        }

        switch (pmic_id) {
        case PMIC_AXP:
                if (on)
                        ret = axp_v1p8_on(subdev->dev, gs);
                else
                        ret = axp_v1p8_off(subdev->dev, gs);
                break;
        case PMIC_TI:
                value = on ? LDO_1P8V_ON : LDO_1P8V_OFF;

                ret = gmin_i2c_write(subdev->dev, gs->pwm_i2c_addr,
                                     LDO10_REG, value, 0xff);
                break;
        case PMIC_CRYSTALCOVE:
                value = on ? CRYSTAL_ON : CRYSTAL_OFF;

                ret = gmin_i2c_write(subdev->dev, gs->pwm_i2c_addr,
                                     CRYSTAL_1P8V_REG, value, 0xff);
                break;
        default:
                dev_err(subdev->dev, "Couldn't set power mode for v1p8\n");
                ret = -EINVAL;
        }

out:
        mutex_unlock(&gmin_regulator_mutex);
        return ret;
}

static int gmin_v2p8_ctrl(struct v4l2_subdev *subdev, int on)
{
        struct gmin_subdev *gs = find_gmin_subdev(subdev);
        int ret;
        int value;

        if (WARN_ON(!gs))
                return -ENODEV;

        if (gs->v2p8_gpio >= 0) {
                pr_info("atomisp_gmin_platform: 2.8v power on GPIO %d\n",
                        gs->v2p8_gpio);
                ret = gpio_request(gs->v2p8_gpio, "camera_v2p8");
                if (!ret)
                        ret = gpio_direction_output(gs->v2p8_gpio, 0);
                if (ret)
                        pr_err("V2P8 GPIO initialization failed\n");
        }

        if (gs->v2p8_on == on)
                return 0;
        gs->v2p8_on = on;

        ret = 0;
        mutex_lock(&gmin_regulator_mutex);
        if (on) {
                gmin_v2p8_enable_count++;
                if (gmin_v2p8_enable_count > 1)
                        goto out; /* Already on */
        } else {
                gmin_v2p8_enable_count--;
                if (gmin_v2p8_enable_count > 0)
                        goto out; /* Still needed */
        }

        if (gs->v2p8_gpio >= 0)
                gpio_set_value(gs->v2p8_gpio, on);

        if (gs->v2p8_reg) {
                regulator_set_voltage(gs->v2p8_reg, 2900000, 2900000);
                if (on)
                        ret = regulator_enable(gs->v2p8_reg);
                else
                        ret = regulator_disable(gs->v2p8_reg);

                goto out;
        }

        switch (pmic_id) {
        case PMIC_AXP:
                ret = axp_regulator_set(subdev->dev, gs, ALDO1_SEL_REG,
                                        ALDO1_2P8V, ALDO1_CTRL3_REG,
                                        ALDO1_CTRL3_SHIFT, on);
                break;
        case PMIC_TI:
                value = on ? LDO_2P8V_ON : LDO_2P8V_OFF;

                ret = gmin_i2c_write(subdev->dev, gs->pwm_i2c_addr,
                                     LDO9_REG, value, 0xff);
                break;
        case PMIC_CRYSTALCOVE:
                value = on ? CRYSTAL_ON : CRYSTAL_OFF;

                ret = gmin_i2c_write(subdev->dev, gs->pwm_i2c_addr,
                                     CRYSTAL_2P8V_REG, value, 0xff);
                break;
        default:

                dev_err(subdev->dev, "Couldn't set power mode for v2p8\n");
                ret = -EINVAL;
        }

out:
        mutex_unlock(&gmin_regulator_mutex);
        return ret;
}

static int gmin_acpi_pm_ctrl(struct v4l2_subdev *subdev, int on)
{
        int ret = 0;
        struct gmin_subdev *gs = find_gmin_subdev(subdev);
        struct i2c_client *client = v4l2_get_subdevdata(subdev);
        struct acpi_device *adev = ACPI_COMPANION(&client->dev);

        /* Use the ACPI power management to control it */
        on = !!on;
        if (gs->clock_on == on)
                return 0;

        dev_dbg(subdev->dev, "Setting power state to %s\n",
                on ? "on" : "off");

        if (on)
                ret = acpi_device_set_power(adev,
                                            ACPI_STATE_D0);
        else
                ret = acpi_device_set_power(adev,
                                            ACPI_STATE_D3_COLD);

        if (!ret)
                gs->clock_on = on;
        else
                dev_err(subdev->dev, "Couldn't set power state to %s\n",
                        on ? "on" : "off");

        return ret;
}

static int gmin_flisclk_ctrl(struct v4l2_subdev *subdev, int on)
{
        int ret = 0;
        struct gmin_subdev *gs = find_gmin_subdev(subdev);
        struct i2c_client *client = v4l2_get_subdevdata(subdev);

        if (gs->clock_on == !!on)
                return 0;

        if (on) {
                ret = clk_set_rate(gs->pmc_clk,
                                   gs->clock_src ? CLK_RATE_19_2MHZ : CLK_RATE_25_0MHZ);

                if (ret)
                        dev_err(&client->dev, "unable to set PMC rate %d\n",
                                gs->clock_src);

                ret = clk_prepare_enable(gs->pmc_clk);
                if (ret == 0)
                        gs->clock_on = true;
        } else {
                clk_disable_unprepare(gs->pmc_clk);
                gs->clock_on = false;
        }

        return ret;
}

static int gmin_csi_cfg(struct v4l2_subdev *sd, int flag)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct gmin_subdev *gs = find_gmin_subdev(sd);

        if (!client || !gs)
                return -ENODEV;

        return camera_sensor_csi(sd, gs->csi_port, gs->csi_lanes,
                                 gs->csi_fmt, gs->csi_bayer, flag);
}

static struct camera_vcm_control *gmin_get_vcm_ctrl(struct v4l2_subdev *subdev,
        char *camera_module)
{
        struct i2c_client *client = v4l2_get_subdevdata(subdev);
        struct gmin_subdev *gs = find_gmin_subdev(subdev);
        struct camera_vcm_control *vcm;

        if (!client || !gs)
                return NULL;

        if (!camera_module)
                return NULL;

        mutex_lock(&vcm_lock);
        list_for_each_entry(vcm, &vcm_devices, list) {
                if (!strcmp(camera_module, vcm->camera_module)) {
                        mutex_unlock(&vcm_lock);
                        return vcm;
                }
        }

        mutex_unlock(&vcm_lock);
        return NULL;
}

static struct camera_sensor_platform_data pmic_gmin_plat = {
        .gpio0_ctrl = gmin_gpio0_ctrl,
        .gpio1_ctrl = gmin_gpio1_ctrl,
        .v1p8_ctrl = gmin_v1p8_ctrl,
        .v2p8_ctrl = gmin_v2p8_ctrl,
        .v1p2_ctrl = gmin_v1p2_ctrl,
        .flisclk_ctrl = gmin_flisclk_ctrl,
        .csi_cfg = gmin_csi_cfg,
        .get_vcm_ctrl = gmin_get_vcm_ctrl,
};

static struct camera_sensor_platform_data acpi_gmin_plat = {
        .gpio0_ctrl = gmin_gpio0_ctrl,
        .gpio1_ctrl = gmin_gpio1_ctrl,
        .v1p8_ctrl = gmin_acpi_pm_ctrl,
        .v2p8_ctrl = gmin_acpi_pm_ctrl,
        .v1p2_ctrl = gmin_acpi_pm_ctrl,
        .flisclk_ctrl = gmin_acpi_pm_ctrl,
        .csi_cfg = gmin_csi_cfg,
        .get_vcm_ctrl = gmin_get_vcm_ctrl,
};

struct camera_sensor_platform_data *
gmin_camera_platform_data(struct v4l2_subdev *subdev,
                          enum atomisp_input_format csi_format,
                          enum atomisp_bayer_order csi_bayer)
{
        u8 pmic_i2c_addr = gmin_detect_pmic(subdev);
        struct gmin_subdev *gs;

        gs = find_free_gmin_subdev_slot();
        gs->subdev = subdev;
        gs->csi_fmt = csi_format;
        gs->csi_bayer = csi_bayer;
        gs->pwm_i2c_addr = pmic_i2c_addr;

        gmin_subdev_add(gs);
        if (gs->pmc_clk)
                return &pmic_gmin_plat;
        else
                return &acpi_gmin_plat;
}
EXPORT_SYMBOL_GPL(gmin_camera_platform_data);

int atomisp_gmin_register_vcm_control(struct camera_vcm_control *vcmCtrl)
{
        if (!vcmCtrl)
                return -EINVAL;

        mutex_lock(&vcm_lock);
        list_add_tail(&vcmCtrl->list, &vcm_devices);
        mutex_unlock(&vcm_lock);

        return 0;
}
EXPORT_SYMBOL_GPL(atomisp_gmin_register_vcm_control);

static int gmin_get_hardcoded_var(struct device *dev,
                                  struct gmin_cfg_var *varlist,
                                  const char *var8, char *out, size_t *out_len)
{
        struct gmin_cfg_var *gv;

        for (gv = varlist; gv->name; gv++) {
                size_t vl;

                if (strcmp(var8, gv->name))
                        continue;

                dev_info(dev, "Found DMI entry for '%s'\n", var8);

                vl = strlen(gv->val);
                if (vl > *out_len - 1)
                        return -ENOSPC;

                strscpy(out, gv->val, *out_len);
                *out_len = vl;
                return 0;
        }

        return -EINVAL;
}


static int gmin_get_config_dsm_var(struct device *dev,
                                   const char *var,
                                   char *out, size_t *out_len)
{
        acpi_handle handle = ACPI_HANDLE(dev);
        union acpi_object *obj, *cur = NULL;
        int i;

        /*
         * The data reported by "CamClk" seems to be either 0 or 1 at the
         * _DSM table.
         *
         * At the ACPI tables we looked so far, this is not related to the
         * actual clock source for the sensor, which is given by the
         * _PR0 ACPI table. So, ignore it, as otherwise this will be
         * set to a wrong value.
         */
        if (!strcmp(var, "CamClk"))
                return -EINVAL;

        obj = acpi_evaluate_dsm(handle, &atomisp_dsm_guid, 0, 0, NULL);
        if (!obj) {
                dev_info_once(dev, "Didn't find ACPI _DSM table.\n");
                return -EINVAL;
        }

        /* Return on unexpected object type */
        if (obj->type != ACPI_TYPE_PACKAGE)
                return -EINVAL;

#if 0 /* Just for debugging purposes */
        for (i = 0; i < obj->package.count; i++) {
                union acpi_object *cur = &obj->package.elements[i];

                if (cur->type == ACPI_TYPE_INTEGER)
                        dev_info(dev, "object #%d, type %d, value: %lld\n",
                                 i, cur->type, cur->integer.value);
                else if (cur->type == ACPI_TYPE_STRING)
                        dev_info(dev, "object #%d, type %d, string: %s\n",
                                 i, cur->type, cur->string.pointer);
                else
                        dev_info(dev, "object #%d, type %d\n",
                                 i, cur->type);
        }
#endif

        /* Seek for the desired var */
        for (i = 0; i < obj->package.count - 1; i += 2) {
                if (obj->package.elements[i].type == ACPI_TYPE_STRING &&
                    !strcmp(obj->package.elements[i].string.pointer, var)) {
                        /* Next element should be the required value */
                        cur = &obj->package.elements[i + 1];
                        break;
                }
        }

        if (!cur) {
                dev_info(dev, "didn't found _DSM entry for '%s'\n", var);
                ACPI_FREE(obj);
                return -EINVAL;
        }

        /*
         * While it could be possible to have an ACPI_TYPE_INTEGER,
         * and read the value from cur->integer.value, the table
         * seen so far uses the string type. So, produce a warning
         * if it founds something different than string, letting it
         * to fall back to the old code.
         */
        if (cur && cur->type != ACPI_TYPE_STRING) {
                dev_info(dev, "found non-string _DSM entry for '%s'\n", var);
                ACPI_FREE(obj);
                return -EINVAL;
        }

        dev_info(dev, "found _DSM entry for '%s': %s\n", var,
                 cur->string.pointer);
        strscpy(out, cur->string.pointer, *out_len);
        *out_len = strlen(cur->string.pointer);

        ACPI_FREE(obj);
        return 0;
}

/* Retrieves a device-specific configuration variable.  The dev
 * argument should be a device with an ACPI companion, as all
 * configuration is based on firmware ID.
 */
static int gmin_get_config_var(struct device *maindev,
                               bool is_gmin,
                               const char *var,
                               char *out, size_t *out_len)
{
        efi_char16_t var16[CFG_VAR_NAME_MAX];
        const struct dmi_system_id *id;
        struct device *dev = maindev;
        char var8[CFG_VAR_NAME_MAX];
        struct efivar_entry *ev;
        int i, ret;

        /* For sensors, try first to use the _DSM table */
        if (!is_gmin) {
                ret = gmin_get_config_dsm_var(maindev, var, out, out_len);
                if (!ret)
                        return 0;
        }

        /* Fall-back to other approaches */

        if (!is_gmin && ACPI_COMPANION(dev))
                dev = &ACPI_COMPANION(dev)->dev;

        if (!is_gmin)
                ret = snprintf(var8, sizeof(var8), "%s_%s", dev_name(dev), var);
        else
                ret = snprintf(var8, sizeof(var8), "gmin_%s", var);

        if (ret < 0 || ret >= sizeof(var8) - 1)
                return -EINVAL;

        /* First check a hard-coded list of board-specific variables.
         * Some device firmwares lack the ability to set EFI variables at
         * runtime.
         */
        id = dmi_first_match(gmin_vars);
        if (id) {
                ret = gmin_get_hardcoded_var(maindev, id->driver_data, var8,
                                             out, out_len);
                if (!ret)
                        return 0;
        }

        /* Our variable names are ASCII by construction, but EFI names
         * are wide chars.  Convert and zero-pad.
         */
        memset(var16, 0, sizeof(var16));
        for (i = 0; i < sizeof(var8) && var8[i]; i++)
                var16[i] = var8[i];

        /* Not sure this API usage is kosher; efivar_entry_get()'s
         * implementation simply uses VariableName and VendorGuid from
         * the struct and ignores the rest, but it seems like there
         * ought to be an "official" efivar_entry registered
         * somewhere?
         */
        ev = kzalloc(sizeof(*ev), GFP_KERNEL);
        if (!ev)
                return -ENOMEM;
        memcpy(&ev->var.VariableName, var16, sizeof(var16));
        ev->var.VendorGuid = GMIN_CFG_VAR_EFI_GUID;
        ev->var.DataSize = *out_len;

        ret = efivar_entry_get(ev, &ev->var.Attributes,
                               &ev->var.DataSize, ev->var.Data);
        if (ret == 0) {
                memcpy(out, ev->var.Data, ev->var.DataSize);
                *out_len = ev->var.DataSize;
                dev_info(maindev, "found EFI entry for '%s'\n", var8);
        } else if (is_gmin) {
                dev_info(maindev, "Failed to find EFI gmin variable %s\n", var8);
        } else {
                dev_info(maindev, "Failed to find EFI variable %s\n", var8);
        }

        kfree(ev);

        return ret;
}

int gmin_get_var_int(struct device *dev, bool is_gmin, const char *var, int def)
{
        char val[CFG_VAR_NAME_MAX];
        size_t len = sizeof(val);
        long result;
        int ret;

        ret = gmin_get_config_var(dev, is_gmin, var, val, &len);
        if (!ret) {
                val[len] = 0;
                ret = kstrtol(val, 0, &result);
        } else {
                dev_info(dev, "%s: using default (%d)\n", var, def);
        }

        return ret ? def : result;
}
EXPORT_SYMBOL_GPL(gmin_get_var_int);

int camera_sensor_csi(struct v4l2_subdev *sd, u32 port,
                      u32 lanes, u32 format, u32 bayer_order, int flag)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct camera_mipi_info *csi = NULL;

        if (flag) {
                csi = kzalloc(sizeof(*csi), GFP_KERNEL);
                if (!csi)
                        return -ENOMEM;
                csi->port = port;
                csi->num_lanes = lanes;
                csi->input_format = format;
                csi->raw_bayer_order = bayer_order;
                v4l2_set_subdev_hostdata(sd, (void *)csi);
                csi->metadata_format = ATOMISP_INPUT_FORMAT_EMBEDDED;
                csi->metadata_effective_width = NULL;
                dev_info(&client->dev,
                         "camera pdata: port: %d lanes: %d order: %8.8x\n",
                         port, lanes, bayer_order);
        } else {
                csi = v4l2_get_subdev_hostdata(sd);
                kfree(csi);
        }

        return 0;
}
EXPORT_SYMBOL_GPL(camera_sensor_csi);

/* PCI quirk: The BYT ISP advertises PCI runtime PM but it doesn't
 * work.  Disable so the kernel framework doesn't hang the device
 * trying.  The driver itself does direct calls to the PUNIT to manage
 * ISP power.
 */
static void isp_pm_cap_fixup(struct pci_dev *pdev)
{
        dev_info(&pdev->dev, "Disabling PCI power management on camera ISP\n");
        pdev->pm_cap = 0;
}
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0f38, isp_pm_cap_fixup);

MODULE_DESCRIPTION("Ancillary routines for binding ACPI devices");
MODULE_LICENSE("GPL");